Background

The ISM gas play a crucial role in high energy particle astrophysics as it provides the target for cosmic-ray collisions which
may lead to many of the TeV gamma-ray sources discovered in the Milky Way by HESS
and other TeV telescopes (see TeVCat for a complete list of TeV gamma-ray sources). An important
aspect of this study concerns dense molecular gas. Via the energy dependent diffusion of cosmic-rays into molecular clouds,
quite specific GeV-TeV gamma-ray spectra and morphology can be expected (e.g. Gabici etal 2007) on the arc-minute scales of
molecular cloud cores and clumps. This presents a new way to probe for Galactic cosmic-rays, their origin, as well as the nature of many Galactic unidentified TeV gamma-ray sources.

The focus of our work since 2008 has been to use
the Mopra telescope (a single dish 22m radio telescope in NSW, Australia)
in the study of dense molecular gas towards TeV (and some GeV)
gamma-ray sources. Gas tracers used include CS(1-0),
SiO(1-0) at 7mm wavelengths (1 arcmin beam FWHM) and the 12mm (2 arcmin beam FWHM) inversion transitions of NH3.

Target List

The targets we have covered so far are listed below. To first order, our Mopra observations cover the full extent of the
TeV/GeV source unless indicated by specific comments or a linked publication. Observations are 'on-the-fly' mapping unless
indicated. Note that Mopra CO Survey (3mm) coverage includes targets within Galactic l=300 to 010 deg, b=-0.5 to +0.5 deg. FITs cubes available for download are corrected
to Mopra's efficiency (according to Urquhart et al 2010) and so are in 'main beam' brightness temperature units - T_mb